Core engaging device



June 1931. R. o. ANDERSON CORE ENGAGING DEVICE Filed June 17, 1929 R. 0.ANDERSON INVENTOK A TTORVE) Patented June 2, 1931 UNITED- STATES REXFORDO. ANDERSON, OF HOUSTON, TEXAS 003E ENGAGING DEVICE Application filedJune 17,

My invention relates to core catches such core, and carry it with thedrill to the surface.

The usual construction of core drill has spring presse d arms orslida'ble jaws to engage the core, but the difliculty with these typesof core catchers is that theljaws are in engagement with the core whilethe drill 10 is rotating and wear materially so that when they are usedto break the core, they sometimes fail to function or become broken.

It is an object of my invention to provide a core catcher having jawsheld normally 1 withdrawn during the operation of the drill,

but capable of being forced into core engaging position when drilling isstopped. I desire to employ the hydraulic pressure of the flushing fluidto hold the core engaging 20 means retracted in use and separate meansto advance the said core engaging means when the fluid circulation isstopped.

Referring to the drawings herewith, Fig. 1 is a central longitudinalsection through a core drill having my invention thereon. Fig. 2 is atransverse section on the plane 22 of Fig. 1. Fig. 3 is an enlargeddetail of the core engaging dog.

The core drill upon which I have shown my device is a scraping type ofsoft formation drill, but my invention is adapted to be used upon anyordinary type of core drill. The bit head 1 has lateral blades 2 to outthe hole. Said head'has a threaded socket 3 to engage a pin or shank 4of a special drill collar 5.

The said drill collar is of tubular construction, the upper end beinginternally threaded at 6 to en age with a drill stem. Below the 40socket 6 there is a smaller threaded seat 7 to receive a collar 8 weldedinto fixed position upon the lower end of the core barrel 9. There arelongitudinal channels 10 in the drill collar leading to passages 11 inthe drill head, so that flushing fluid may be discharged upon thecutters at the bottom of the hole.

The core engaging device includes a plurality of dogs 12, each pivotedupon a pin 13, mounted in a small housing 14 fitted so slidably withinone of the recesses 15 in the 1929. Serial No. 371,348.

wall of the drill collar. The housings 14 are shaped to fit saidrecesses, and have a central opening 16 therein to receive the dog 12.-At the lower end, the housin has a small downwardly projecting post 1%is slidable within a sleeve 18 having a base 19, supported upon thebottom of the recess I 16. The post 14 has a radial pin 20 thereonfitting within a bayonet slot 21 in said sleeve 18. The held upwardly inthe recess by a spring 22 compressed between the lower end of saidhousing and the base 19 of said sleeve 18. The pin 20 is movablevertically in said slot I 21, but if the housing is removed from thecollar, the post may be rotated into the lateral branch 23 of the slotand removed therefrom.

The dogs 12 are formed with an inwardly curved nose 24 adapted to extendthrough an opening or window 25 in the inner wall of the recess 15, soas to engage the core-26. Above the dogs in the housing is a'frictionspring 27 secured to the upward wall of the opening 16 and adapted tobear against the curved upper end of the dog, and tend to move said doginwardly against the core.

Above the housing 14 is a cylindrical passage 29 connectin with thewatercourse 30 in the collar 5. or purposes of construction, the drillcollar is made in sections welded together along the upper line of thecylinder 29. Said cylinder receives a piston 31 which is slidabletherein and bears against the upper end of the housing 14.

When the drill is in use the spring 22 below the housing 14 tends tomove the said housing, and the dogs 12 upwardly so as to move the saiddog into core engaging position as shown in dotted lines in Fig. 1. But11:.) the pressure of the flushing fluid upon the piston 31 is exertedupon the housing, depressing sprin 22, and holding the dogs 7 withdrawn.en the core isto be broken off, and brought to the surface, the pumpsare stopped and when the pressure upon the piston 31 is thus removed;the spring 22. acts to force the do s 12 upwardly and the spring 27moves the 0g inwardly so that the nose thereof, engages into the core asshown in post and housings are .normallygo I Fig. 1, and the core'isthus broken o-fi' and withdrawn. There may be any desired num ber ofcore engaging dogs. I have shown three in Fig. 2 and ordinarily thisnumber will be satisfactory. V

This device will not be subject to material Wear and as the dogs areresiliently mounted, little likelihood of breakage will be experienced.The housings for the dogs are mounted in their recesses in any desiredmanner. I have shown an outer detachablesleeve 32 upon the drill collarwhich may be removed to obtain access to the dogs, but I do not wish tobe confined to the details of construction described.

What I claim as new is:

1. A core drill including a core bit and a drill collar thereon incombination with housings mounted to slide vertically in said drillcollar. dogs on said housings adapted to be held retracted by liquidpressure and means to move said housings to project said dogs into coreengaging position.

2. A core drill including a core bit and a drill collar thereon, incombination with housings mounted to slide vertically downwardly in saiddrill collar, dogs on said housings adapted to project inwardly tocontact with a core, means to move said housings uprated through pumppressure to hold said Wardly to project said dogs into core engagingposition, and means actuated by liquid pressure to hold said dogs inposition withdrawn from core engagement while the said drill isrotating.

3. In a core drill having a tubular head and drill collar thereon, thecombination of core engaging dogs mounted forvertical movement relativeto said drill, means to project said dogs'inwardly when they are raised,and hydraulically operated means to hold said dogs depressed.

4. In a core drill having a tubular head and drill collar thereon, thecombination of core engaging dogs mounted .for vertical movementrelative to said drill, means operdogs depressed when said drill isoperating.

5. In a core drill having a tubular head and drill collar thereon, thecombination of core engaging dogs mounted for vertical movement relativeto said drill, resilient means tending to raise said dogs relative tosaid drill, means to project said dogs inwardly when they are raised,and hydraulically operated means to hold said dogs depressed.

6. In a device of the character described, core-engaging dogs housed outof the ath of the core, resilient supports for said ogs, tending to movesaid dogs upwardly, and means to project said dogs inwardly when saiddogs are moved upwardly.

.7. In a device of the character described I core-engaging dogs housedout of the path 0% the core, hydraulically operated means to Intestimony whereof, I hereunto aflix my signature this 11th day of JuneA. D. 1929.

REXFORD O. ANDERSON.

